(05-15) 20:42 PDT SAN FRANCISCO -- A 17-year-old girl described as developmentally disabled went missing Sunday morning during the Bay to Breakers race, but her father said she returned home on her own Sunday evening.

Separated from her family since around 10:40 a.m., Olivia Ostergard was found when she simply walked through the front door of the family home just before 8 p.m., said Chris Ostergard.

"She seems to be very happy and healthy and appears unharmed," he said as his daughter was about to be interviewed for precautionary reasons by a police officer.

Authorities and her family had been particularly concerned because Olivia Ostergard had been described by officers as having the mental capacity of a 9-year-old.